The present invention relates to an improved break down tong apparatus. More particularly, the present invention relates to a power tong apparatus and a cooperating backup tong apparatus for breaking connections between links of pipe as the pipe is being removed from the ground.
It is well known to push a rod or pipe through the ground with a drilling rig from one location to another predetermined location beneath the surface of the ground. For example, a pipe may be pushed under a road from one side of the road to another without creating a trench in the road. Generally speaking, apparatus for directing forward movement of a pipe through the ground beneath the surface of the ground are known in the art. Drilling rigs are also used to drill into the ground for oil wells or the like. Typically, these drilling rigs rotate the pipe in a counterclockwise direction or a clockwise direction to install or remove pipe from the ground.
Making and breaking apparatus are known for making up or breaking out joints between adjacent pipes which are driven into the ground with known drilling rigs. As the pipe is being removed from the ground, joints between adjacent sections must be loosened to permit the next section of pipe to be removed from the ground.
The power tong apparatus of the present invention includes two separate tongs operating in conjunction with each other. A backup tong is provided to grip and hold a lower section of pipe which extends into the ground stationary. A power tong is provided to grip and rotate an upper section of pipe which is connected to the lower section of pipe in the ground. While the backup tong prevents rotation of the lower length of pipe, the power tong grips and rotates the upper section of pipe to break the joint between the upper and lower pipe sections.
According to one aspect of the present invention, a tong apparatus is provided for gripping a pipe. The apparatus includes a base, and a support rigidly coupled to the base. The support is formed to include an aperture for receiving the pipe. The apparatus also includes a plurality of rollers rotatably coupled to the support adjacent the aperture. Each roller includes a plurality of teeth configured to engage the pipe. The apparatus further includes a movable actuator coupled to the support, and a plurality of wedge plates rigidly coupled to the actuator. Each wedge plate includes a plurality of teeth configured to engage the teeth of a corresponding roller to force the rollers radially inwardly against the pipe to grip the pipe upon movement of the actuator relative to the support. The apparatus still further includes a cylinder having a piston coupled to the actuator. The piston is movable from an extended position to a retracted position to move the actuator relative to the support.
In the illustrated embodiment, the apparatus includes an elastic band coupled to the plurality of rollers and to the support to apply a radially outwardly directed force to the rollers to hold the rollers away from the pipe when the wedge plates are disengaged from the rollers. The plurality of wedge plates and the plurality of rollers are preferably made from a heat treated metal material.
Also in the illustrated embodiment, the support includes a first support plate coupled to the base, and a second support plate rigidly coupled to the base spaced apart from the first support plate. The teeth of the plurality of rollers are located between the first and second support plates. The first and second support plates each include a plurality of elongated slots for receiving opposite ends of the plurality of elongated rollers therein.
The actuator includes an annular body surrounding the plurality of rollers. The annular body is rotatably coupled between the first and second support plates. The wedge plates are configured to engage the rollers upon rotation of the actuator relative to the first and second support plates in either direction.
In another illustrated embodiment, the support includes a fixed support rigidly coupled to the base and a rotatable support coupled to the fixed support. The plurality of rollers are coupled to the rotatable support so that the rollers grip and rotate the pipe relative to the fixed support upon movement of the actuator. At least one spring is coupled between the actuator and the rotatable support to prevent rotation of the rotatable support until the teeth of the rollers engage the pipe upon movement of the actuator by the piston. The rotatable support rotates relative to the fixed support after the rollers grip the pipe to rotate the pipe upon further movement of the actuator by the piston.
In the illustrated embodiment, an arm is coupled to the rotatable support. The arm is also coupled to one end of the spring. A first stop is coupled to the fixed support to engage the arm and block movement of the rotatable support in a first direction to permit disengagement of the wedge plates from the rollers to release the pipe. A second is stop coupled to the fixed support to engage the arm and block movement of the rotatable support in a second direction to permit a main drive to break itself loose from the pipe.
According to another aspect of the present invention, a break down tong apparatus is provided for breaking loose a joint connection between a first pipe and an adjacent second pipe. The apparatus includes a base and a backup tong having a first support rigidly coupled to the base. The first support is formed to include a first aperture for receiving the first pipe. The backup tong also includes a first set of rollers rotatably coupled to the first support. Each first roller includes a plurality of teeth configured to engage the first pipe. The backup tong further includes a movable first actuator coupled to the first support. A first set of wedge plates are rigidly coupled to the first actuator. Each wedge plate includes a plurality of teeth configured to engage the teeth of a corresponding first roller to force the first rollers radially inwardly against the first pipe to grip the first pipe upon movement of the first actuator relative to the first support. The backup tong still further includes a first cylinder having a first piston coupled to the actuator. The first piston is movable from an extended position to a retracted position to move the first actuator relative to the first support. The break down tong apparatus also includes a power tong having a fixed support rigidly coupled to the base and a rotatable support coupled to the fixed support. The rotatable support is formed to include a second aperture for receiving the second pipe. A second set of rollers is rotatably coupled to the rotatable support adjacent the second aperture. Each second roller includes a plurality of teeth configured to engage the second pipe. The power tong also includes a movable second actuator coupled to the fixed support, and a second set of wedge plates rigidly coupled to the second actuator. Each second wedge plate includes a plurality of teeth configured to engage the teeth of a corresponding second roller to force the second rollers radially inwardly against the second pipe to grip the second pipe upon movement of the second actuator relative to the fixed support. The power tong apparatus still further includes a second cylinder having a second piston coupled to the actuator. The second piston is movable from an extended position to a retracted position to move the actuator relative to the fixed support to rotate the second pipe relative to the first pipe to break the joint connection between the first pipe and the second pipe.
In the illustrated embodiment, the apparatus further includes a bearing surrounding the first pipe. The bearing is located adjacent the backup tong on an opposite side of the backup tong from the power tong.
At least one spring is coupled between the second actuator and the rotatable support to prevent rotation of the rotatable support until the teeth of the second rollers engage the second pipe upon movement of the second actuator by the second piston. The rotatable support rotates relative to the fixed support after the second rollers grip the second pipe to rotate the second pipe upon further movement of the second actuator by the second piston.
The apparatus still further includes a sequence control valve for actuating, in sequence, the first cylinder to move the first piston to cause the first set of rollers to engage the first pipe, then actuating the second cylinder to move the second piston to cause the second set of rollers to engage the second pipe. The sequence control valve further moves the second piston to cause rotation of the rotatable support relative to the fixed support to break the joint connection between the first pipe and the second pipe. The sequence control valve then actuates the second cylinder to move the second piston to release the second set of rollers from the second pipe before the first cylinder is actuated to release the first set of rollers from the first pipe to permit a main drive coupled to the second pipe to rotate the second pipe to uncouple the first pipe from the second pipe. The sequence control valve next actuates the second cylinder to move the second piston to its extended position after the first and second joint portions are uncoupled to permit the main drive coupled to the second pipe to break itself loose from the end of the second pipe.
The apparatus includes an arm coupled to the rotatable support. The arm is coupled to one end of the spring. A first stop is coupled to the fixed support to engage the arm block movement of the rotatable support in a first direction to permit disengagement of the wedge plates from the rollers to release the pipe. A second stop is coupled to the fixed support to engage the arm and block movement of the rotatable support in a second direction to permit a main drive to break itself loose from the pipe.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of the preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.